Subject:
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Re: NXT and bluetooth enabled phones
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Newsgroups:
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lugnet.robotics
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Date:
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Tue, 17 Jan 2006 00:06:44 GMT
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Viewed:
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1653 times
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On 16/01/2006, at 11:38 PM, Roger Glassey wrote:
> In lugnet.robotics, PeterBalch <PeterBalch@compuserve.com> wrote:
>
> > I've avoided Java because, for Windows applications, I'm very
> > happy with
> > Delphi and, for robots, Java requires a ludicrously huge virtual
> > machine.
> Not really. Take a look at Lejos. After the VM has been
> downloaded to the RCX, you have about 14K memory for the Java byte
> code. Which is enough for some pretty complicated stuff.
Lejos is not a full JVM - it has no garbage collector, e.g., and the
standard library is mostly absent. I doubt Sun would certify it as an
implementation of the Java platform.
(Not to knock their technical achievement - it is quite impressive -
just that it's not Java.)
> > I'd learn Java script for web-based applets (if only I could get
> > it running
> > on my PC) but otherwise, why should I want Java?
>
> Because it is Object Oriented which allows for greater modularity
> of code, and
> the possibility of debugging chunks of it independently. And if you
> can put the
> top level logic in a its own set of objects, they can be tested on
> your PC.
<scratches head> OO is not the only way to do this. It is not clear
to me that the overheads of Java (relative to say a brickOS / C
combination) are worth it on the RCX, especially as you have to
manage memory manually in both cases anyway.
What, you think C is non-modular and generally sucks? Well... you
could generate C code from some other, more pleasant language -
people have been doing this for years. The advantage is that the poor
RCX doesn't have to labour under the weight of a virtual machine (a
JVM, the Lego bytecode interpreter).
(I'll stop here.)
cheers
peter
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Message has 1 Reply:
 | | Re: NXT and bluetooth enabled phones
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| Hi Peter, (...) no, it can't be. (...) That is the top item on my list to add to Lejos, and on NXT it is possible :-) In Lejos we figured it would have eaten so much memory that there wouldn't have been much point in managing the rest. (...) Yes. On (...) (18 years ago, 17-Jan-06, to lugnet.robotics)
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Message is in Reply To:
| | Re: NXT and bluetooth enabled phones
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| (...) Not really. Take a look at Lejos. After the VM has been downloaded to the RCX, you have about 14K memory for the Java byte code. Which is enough for some pretty complicated stuff. (...) Because it is Object Oriented which allows for greater (...) (18 years ago, 16-Jan-06, to lugnet.robotics)
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